1. Field of Invention
The present invention relates to a misfuelling prevention apparatus for vehicles. More particularly, the present invention relates to a misfuelling prevention apparatus for vehicles that can prevent a diesel vehicle from being filled with a wrong fuel.
2. Description of Related Art
In general, fuel tanks for storing a fuel necessary for combustion of an engine are provided in vehicles. The fuel tank is connected to an oil filling pipe and a fuel filler neck, i.e., an oil filling port, is provided at an end of the oil filling pipe so that a fuel can be filled into the fuel tank through the fuel filler neck. Oil guns for filling a fuel into a fuel filler neck have different diameters according to whether the fuel is a gasoline fuel or a diesel fuel, and the oil filling speeds are also different.
In general, the diameter of an oil gun for a diesel fuel is larger than the diameter of an oil gun for a gasoline fuel. Accordingly, the diameter of the fuel filler neck for a diesel vehicle is larger than the diameter of the fuel filler neck for a gasoline vehicle.
For example, the oil gun for a diesel fuel has a diameter of about 25 mm to 31 mm, and the oil gun for a gasoline fuel has a diameter of about 19 mm to 21 mm. The fuel filling port for a gasoline vehicle has a diameter of about 22 mm, and the fuel filling port for a diesel vehicle has a diameter of about 26 to 32 mm.
Thus, an oil gun for a diesel fuel cannot be inserted into a gasoline vehicle but only an oil gun for a gasoline fuel can be inserted into the gasoline vehicle so that a misfuelling problem does not occur, but since an oil gun for a gasoline fuel as well as an oil gun for a diesel fuel can be inserted into a fuel filling port of a diesel vehicle, a misfuelling problem frequently occurs.
Meanwhile, diesel fuels have been mainly used for large vehicles conventionally, but since cars also have used diesel fuels recently and self-fuelling increases due to high oil prices, cases of filling gasoline into diesel vehicles in gas stations are increasing.
Nowadays, as fuelling costs are increasing, the number of gas stations where drivers fill fuels by themselves is also increasing. In self-service gas stations, a plurality of oil filling sites are disposed such that drivers can directly fill fuels into their vehicles, so that conveniences of drivers can be satisfied.
However, since a gasoline gun for filling a gasoline fuel and a diesel gun for filling a diesel fuel are provided in one oil filling site and two fuel filling switches for selecting kinds of oil are provided in the oil guns, a misfuelling problem of mixing fuels frequently occur when drivers selects a wrong oil gun or a wrong fuel filling switch.
In this way, when a fuel is filled in a diesel vehicle, gasoline misfuelling accidents actually occur frequently. The misfuelling may lower an output of an engine and directly damage the engine, and may stop an operation of the engine during driving, causing a large-size accident. Further, the misfuelling may cause damage to a fuel system such as an injection pump.
In view of the aspect, U.S. Patent Application Publication No. 2012/0211489 A1 discloses that when a diesel gun having a large diameter is inserted, it pushes a boss at an upper portion of a stopper while rotating the stopper and opening a flapper. U.S. Pat. No. 7,661,550 B2 discloses that if a diesel gun having a large diameter is inserted, it pushes a boss and rotates a circumferential structure so that slots formed on left and right sides of the structure open a stopper. U.S. Pat. No. 7,967,042 B2 discloses that when a diesel gun having a large diameter is inserted, it pushes a plurality of circumferential bosses and rotates an external structure to open a stopper.
However, the conventional technologies do not consider inserting a diesel gun having a diameter of 31 mm, and are disadvantageous in the structural and operational aspects. Further, even when a gasoline gun having a small diameter is inserted, an oil filling port may be opened. That is, they cannot ensure the prevention of misfuelling.
The information disclosed in this Background section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.